XM-19 is a nitrogen-strengthened, high-manganese, molybdenum-bearing austenitic chromium-nickel stainless steel (nominally 22% chromium, 13% nickel, 5% manganese with molybdenum, niobium, vanadium and nitrogen — the "22-13-5" composition) that combines high strength with corrosion resistance superior to the standard molybdenum austenitic grades. This datasheet presents the material within the American standard system.
Its room-temperature yield strength is about twice that of the 316/316L and 317/317L grades (and up to about three times in the cold-worked condition), achieved through nitrogen and manganese strengthening rather than through molybdenum alone. Its general and crevice corrosion resistance is superior to the 316/316L and 317/317L grades, with a Pitting Resistance Equivalent Number (PREN) above 34 — on a par with 2205-type duplex stainless steel. The high manganese and nitrogen stabilise the austenite so effectively that the alloy remains non-magnetic even after severe cold work or at sub-zero temperatures, and it retains good mechanical properties from cryogenic to elevated temperatures. As with most austenitic stainless steels, it can be susceptible to stress-corrosion cracking in hot chloride-bearing environments.
It is readily welded by conventional processes using a matching over-alloyed filler; autogenous high-power-density processes such as electron-beam and laser welding are approached with caution. Typical applications include fasteners, bolting and shafting, chains, pump and valve components, flanges, springs, marine hardware, petrochemical equipment and medical implants.
| Property | Value | Unit |
|---|---|---|
| Density | 7.88 | g/cm³ |
| Melting range | 1390–1440 | °C |
| Young's modulus (20 °C) | 196 | GPa |
| Thermal conductivity (20 °C) | ~13 | W/m·K |
| Coefficient of thermal expansion (20–100 °C) | ~15.3 | µm/m·°C |
| Electrical resistivity (20 °C) | ~0.72 | µΩ·m |
| PREN (Cr + 3.3×Mo + 16×N) | >34 | — |
| Magnetic response | Non-magnetic | — |
| Element | Symbol | Min % | Max % | Role in Alloy |
|---|---|---|---|---|
| Iron | Fe | Balance | — | Base element |
| Chromium | Cr | 20.5 | 23.5 | Passivity; pitting resistance |
| Nickel | Ni | 11.5 | 13.5 | Austenite stability |
| Manganese | Mn | 4.0 | 6.0 | Austenite stabiliser; non-magnetic stability |
| Molybdenum | Mo | 1.5 | 3.0 | Pitting + crevice corrosion resistance |
| Nitrogen | N | 0.20 | 0.40 | Solid-solution strengthening; pitting; austenite |
| Niobium | Nb | 0.10 | 0.30 | Strengthening; carbide control |
| Vanadium | V | 0.10 | 0.30 | Strengthening |
| Silicon | Si | — | 1.0 | Deoxidiser |
| Carbon | C | — | 0.06 | Controlled |
| Phosphorus | P | — | 0.040 | Residual impurity |
| Sulphur | S | — | 0.010 | Residual impurity |
Typical room-temperature properties, annealed condition.
| Property | Value | Source |
|---|---|---|
| Ultimate tensile strength | ~690–760 MPa | Annealed |
| 0.2% proof strength (yield) | ~415–450 MPa | Annealed |
| Elongation at break | ~35–45 % | Annealed |
| Hardness | ~95 HRB | Annealed |
| Cold-worked yield | up to ~3× 316L | Cold-worked |
Room-temperature yield strength is about twice that of 316/316L and 317/317L (up to three times when cold-worked), with good properties from cryogenic to elevated temperatures. Values are typical; confirm against the mill test certificate.
| Environment | Performance | Notes |
|---|---|---|
| General corrosion | Superior to 316/316L, 317/317L | — |
| Pitting (chlorides) | Excellent | PREN > 34 |
| Crevice corrosion | Superior to 316/316L | — |
| Marine environments | Excellent | Outstanding in harsh marine service |
| Hot chloride SCC | Susceptible | As for 304/316 austenitics |
| Magnetic stability | Excellent | Non-magnetic after severe cold work |
| Sub-zero / elevated temperature | Good | Retains properties both extremes |
An austenitic stainless steel; it cannot be hardened by heat treatment. High strength comes from nitrogen, manganese, niobium and vanadium; strength can be raised further by cold work.
Solution Anneal about 1065 °C (1950 °F) gives adequate corrosion resistance with high strength for many applications; for as-welded service or very corrosive media, the 1121 °C (2050 °F) anneal is preferred. Follow with rapid cooling (water quench).
Material in the high-strength cold-worked condition is often specified for bolting and shafting, with a small compromise in corrosion resistance versus the annealed condition. Hot working is done at 1177–1204 °C (2150–2200 °F).
Readily welded by conventional processes — gas-tungsten-arc, gas-metal-arc, shielded-metal-arc and submerged-arc — using a matching over-alloyed filler, Nitronic 50W. Caution is required with autogenous high-power-density processes such as electron-beam and laser welding, owing to low ferrite number and nitrogen outgassing.
| Process | Applicability | Filler / Consumable |
|---|---|---|
| GTAW / TIG · GMAW / MIG | Good | Nitronic 50W |
| SMAW · SAW | Good | AWS E/ER209-type consumable |
| Electron-beam / laser | Caution | Low FN + nitrogen outgassing |
No preheat required. Use matching over-alloyed filler to maintain strength and corrosion resistance.
Machining Guidelines
| Parameter | Recommendation |
|---|---|
| Machinability | Similar to other austenitics but high work-hardening; slower speeds, more power, high rigidity |
| Tooling | Coated carbide tooling recommended |
| Work hardening | Very high; positive feeds, avoid dwelling |
| Coolant | Ample flood coolant |
Forming Processes
| Process | Notes |
|---|---|
| Hot working / forging | 1177–1204 °C (2150–2200 °F); more power than 304 |
| Cold forming | More power needed; high work-hardening |
| Solution anneal | 1065 °C (general) / 1121 °C (max corrosion), water quench |
| Industry | Typical Components | Key Requirements |
|---|---|---|
| Fasteners / fittings | Bolting, fasteners, shafting, chains | High strength + corrosion resistance |
| Pumps & valves | Pump shafts, valve components, flanges | Strength + crevice/pitting resistance |
| Marine | Marine hardware, fittings | Chloride pitting + strength |
| Petrochemical / oil & gas | Sour-service components | Corrosion + strength; PREN > 34 |
| Springs | Springs, wire forms | High strength; non-magnetic |
| Medical | Implants | Strength + corrosion + low magnetic permeability |
| Product Form | Standard | Notes |
|---|---|---|
| Bar and wire | ASTM A276 / A479 · AMS 5764 | S20910 / XM-19 |
| Plate, sheet and strip | ASTM A240 / A412 | — |
| Forgings and fittings | ASTM A182 | — |
| Bolting / fasteners | ASTM A193 / A194 / A453 | — |
| Sour service | NACE MR0175 | Acid-gas applications |
Nitrogen-strengthened 22-13-5 austenitic stainless steel. UNS S20910; AMS 5764; ASTM A276 / A240 / A182 / A193; NACE MR0175. Tradenames: Nitronic 50, Alloy 50, Fermonic 50.
| UNS | Nominal | PREN | Best Used For |
|---|---|---|---|
| XM-19 | 22Cr-13Ni-5Mn-Mo-Nb-V-N | >34 | 2× 316L yield + superior corrosion |
| S21900 | 21Cr-6Ni-9Mn-N | ~28 | High strength, non-mag (no Mo) |
| S31603 | 17Cr-12Ni-2Mo | ~24 | General Mo stainless (reference) |
| S31703 | 18Cr-13Ni-3Mo | ~30 | Higher-Mo stainless (reference) |
| S32205 | 22Cr-5Ni-3Mo-N | ~35 | Duplex (similar PREN, higher strength) |




